Reducing your lighting is the last thing I'd do. Although BTAs are not as needy as most other anemones, they still need lots of light. If they are getting too much, you will know because they will move until they are in a shaded part. However, mine is directly under LEDs at about 600 PAR and is loving it. Definitely feed it, but I'm not sure how much good krill will do. Try mysis if you have it.
Are you sure that it is bleaching? You say brown, which sounds like it is darker than what it currently is. Light green is not normally a good color for a BTA. It's possible that the green was a bleached color and it is slowly getting healthy again. It might actually be a bleached RBTA.
CJ